This study developed a novel urethane acrylate-based 3D printing resin incorporating a custom-synthesized zirconium (IV) fluoride complex designed to confer simultaneous antibacterial activity and sustained fluoride release. The complex was synthesized from 4,4-bis-(4-hydroxyphenyl)-pentanoic acid, characterized by ¹H NMR, and incorporated at 5 and 10 wt% into a DLP-printable resin matrix. Flexural strength, Vickers hardness, surface morphology, antibacterial efficacy against S. mutans, cytotoxicity, and daily fluoride release over 28 days were systematically evaluated. Results demonstrated concentration-dependent fluoride release at clinically relevant low levels, acceptable antibacterial performance, and no detectable cytotoxicity, though mechanical properties were significantly affected by complex addition. These findings establish a compositional foundation for multifunctional 3D-printed dental restorations — including crowns, bridges, and orthodontic appliances — capable of delivering long-term cariostatic and antimicrobial benefits.

This study evaluated the effect of incorporating the quaternary ammonium monomer DMAHDM into a urethane acrylate-based 3D printing resin, with particular focus on how thermal aging modifies its performance over simulated clinical service. DMAHDM was added at concentrations of 0.25–1 wt%, and specimens were subjected to up to 5000 thermal cycles to simulate long-term intraoral aging. Degree of conversion, color stability, flexural strength, Vickers hardness, antibacterial effectiveness, and cytotoxicity were systematically assessed. Results revealed concentration- and aging-dependent trade-offs: higher DMAHDM levels and extended aging enhanced hardness and antibacterial activity but progressively compromised flexural strength and biocompatibility, while also inducing notable color shifts. These findings highlight the need to carefully balance DMAHDM concentration against aging-related property changes when designing antimicrobial 3D-printed dental resins for durable clinical use.

This study investigated how postwashing method and duration affect the mechanical performance and biocompatibility of DLP-printed crown and bridge resins. Specimens were washed using either an ultrasonic bath or a rotary washer with TPM solvent across five time points (3, 6, 10, 20, and 60 minutes), followed by standardized postcuring. Flexural strength, Vickers hardness, degree of conversion, water sorption and solubility, residual monomer elution, and cytotoxicity were comprehensively evaluated. The ultrasonic bath demonstrated superior monomer removal efficacy, reducing residual HEMA and TEGDMA to near-negligible levels. However, extended washing progressively compromised mechanical properties and degree of conversion, while cytotoxicity decreased with longer washing times. These findings highlight the importance of optimizing both washing method and duration to balance structural integrity and biological safety in clinical 3D printing workflows.